SanDisk isn’t premium at all. And known for various issues.
It's only their high-end stuff that was decent. For a long time, they were kings of the high-end CompactFlash and SD card market for photo/video work with their Extreme and Ultra lines. Lexar was the other major player there.
A lot of other companies offered cheaper, better performing products particularly for USB flash drives.
https://www.swissbit.com/en/products/nand-flash-products/usb...
So "should be" is not very enticing, especially if they want to charge 10x. As far as I can tell you can get generic flash chips and run them as SLC, so they should only need 3x the flash and 1x as much everything else.
And actually looking at the prices here, it's about $120 for 32 gigacells. If you get the SLC model then you're not paying 10x the cost per byte, you're paying 40x the cost per byte.
No, (2^3)x, as in 8x
TLC flash puts 3 bits into each cell. It's 3x as dense. The fact that it uses 8 voltage levels is only relevant to performance and durability.
(Also 2^1 versus 2^3 is not 8x anyway.)
BTW, there is no need to buy anything fancy for RPi, I just buy the cheap stuff, but I buy much higher capacity than what I need. Overprovisioning this way is cheaper and more reliable in my opinion vs. buying something more exotic.
For example for the most basic RPi install, I'll buy a 64GB microSD card. The card may only ever see less than 10 GB worth of data, but I know it'll last for years with plenty of chatty logs written to it daily.
Source: I've been running RPis from the very first version, and have never had a single card fail on me, ever.
- Reliable chips were placed in name-brand products
- Defective chips have the defective parts disabled, and were placed in products on tier down. A 16MB chip might be sold as an 8MB.
- Unreliable chips were given various error correcting techniques, and are placed in cheap, off-brand parts, as well as non-critical applications (such as, at the time, answering machines). A common technique was to scatter addresses, so errors were randomly distributed. For answering machines, this meant a little bit of static. For other applications, this meant a bit of ECC would make them quasi-reliable.
Cards and chips down the line failed a lot more than at the top.
I have had a few memory cards fail before. I am glad to pay for top-line parts. The premium I'm willing to pay is in the low tens of dollars, which is what Sandisk used to do.
I found non-A1/A2 cards to be significantly slower, so these days I ensure they're at least A1 rated.
You might also look specifically for "Windows To Go Certified" flash drives - not because you're actually going to run Windows from them but because they should meet some decent minimums for speed and flash endurance.